1. Field of the Invention
The present invention relates to a wiper for sweeping off surfaces of glasses of a vehicle.
2. Description of the Background Art
In a conventional wiper, as a running speed of a vehicle is increased, a lift acting on a wiper blade increases. In order to prevent the floating of the wiper blade off a glass surface due to the lift, a variable thrust pressure type wiper has been proposed, in which the pushing pressure of a wiper blade against a glass surface can be varied corresponding to a running speed increase of a vehicle, as disclosed in Japanese Patent Laid-Open Specification No. 56-60751.
There is shown in FIG. 1 one example of a conventional variable thrust pressure type wiper. In FIG. 1, an arm head 1 is pivotally mounted on a wiper shaft 2 so as to pivot around the wiper shaft 2. The arm head 1 is mounted with a wiper section which comprises a wiper arm 4 pivotally connected to the arm head 1 through a pivot shaft 3 and a wiper blade (not shown) mounted to the wiper arm 4. The wiper blade is provided with a contact wiper member composed of rubber or the like, and the contact wiper member is contacted to the glass surface of the vehicle. By pivoting the arm head 1 around the wiper shaft 2 within a certain pivot angle using a driver (not shown) such as a motor, the contact wiper member contacts and wipes or sweeps off the glass surface to remove waterdrops and so forth attached to the glass surface.
The arm head 1 and the wiper arm 4 connected thereto via the pivot shaft 3 constitute a wiper body 5, and a device for adjusting a thrust pressure of the contact wiper member of the wiper blade against the glass surface is arranged within the wiper body 5. The thrust pressure adjusting device includes a pair of coil springs 6a and 6b, a pair of L-shaped levers 7a and 7b, a lever shaft 8, a link rod 9, a movable link member 10 and a geared motor 11. That is, one ends of the coil springs 6a and 6b are secured to the wiper arm 4, and the other ends of the coil springs 6a and 6b are linked to the L-shaped levers 7a and 7b, respectively. The L-shaped levers 7a and 7b are pivotally mounted to the lever shaft 8 and are connected to the link rod 9. The link rod 9 is coupled to the movable link member 10, and the movable link member 10 is connected to the geared motor 11 for moving the movable link member 10 to and from the geared motor 11.
Now, when the geared motor 11 is driven to move the movable link member 10 towards the geared motor 11, the link rod 9 coupled to the movable link member 10 rotates counterclockwise the L-shaped levers 7a and 7b around the lever shaft 8 at different timings. Then, the coil springs 6a and 6b are extended by the L-shaped levers 7a and 7b, respectively, at the different timings to vary the tensions of the coil springs 6a and 6b, thereby adjusting the pushing pressure of the contact wiper member of the wiper blade against the glass surface.
In the conventional wiper shown in FIG. 1, a cord 13 for supplying electric power to an electric circuit for the geared motor 11 and the like is connected to the arm head 1 and is mounted to a peripheral portion of the arm head 1 by using a clip 14 or the like. When the arm head 1 is pivoted around the wiper shaft 2 within a certain pivot angle, the cord 13 is repeatedly bent near the clip 14, and hence in a long period of time of use under hard conditions, the bent portion of the cord 13 is apt to be damaged, e.g., broken or cut.
In another conventional wiper, as shown in FIG. 2, the cord 13 is covered by a flexible protective composed of a polyvinyl resin material or the like to form a harness 15. This harness 15 is drawn out of the arm head 1 in a direction perpendicular to the side surface of the arm head 1 and is mounted in a location apart from the side surface of the arm head 1 by using a clip 16 or the like.
However, in this case, a similar problem to that of the conventional wiper shown in FIG. 1 arises. That is, as shown in FIG. 2b, when the arm head 1 is pivoted in a clockwise direction, the harness 15 is extremely bent near the arm head 1 to damage the extremely bent portion.